1. Technical Field
The present invention relates to sidewall image transfer (SIT) technologies, and more specifically, to improvements to SIT technologies.
2. Related Art
In a conventional sidewall image transfer (SIT) process, a memory region is formed from a memory layer and then used as a blocking mask for etching one or more layer beneath the memory region so as to transfer the image of the memory region down to the underlying layer(s). The formation of the memory region from the memory layer involves a planarization-and-etchback step. However, the planarization-and-etchback step may damage the memory region due to pattern density variation on the wafer. Therefore, there is a need for improvements to sidewall image transfer (SIT) technologies that are not affected by pattern density variation on the wafer.